MINDSETMonths to result

Hamilton's Rule Framework

Altruism Evolves

Problem it solves

limiting beliefs

Best for

Understanding the evolution of altruism and cooperation

Not ideal for

Simple decision-making or non-evolutionary contexts

Overview

Why this framework exists

Hamilton's rule is a mathematical formula that predicts when altruism will evolve in a population. It states that altruism will evolve when the cost to the actor is less than the benefit to the recipient, multiplied by the probability that the recipient carries a copy of the gene for altruism. This framework helps explain the evolution of cooperation and altruism in humans and other animals.

Core principles

3 total
  1. Altruism evolves when the cost to the actor is less than the benefit to the recipient, multiplied by the probability that the recipient carries a copy of the gene for altruism.
  2. Kin selection is a key driver of the evolution of altruism.
  3. The degree of genetic relatedness between individuals affects the likelihood of altruism.

Steps

4 steps
  1. Calculate the cost to the actor
    Determine the cost to the individual performing the altruistic act.
    Pro tipConsider the potential risks and benefits to the actor.
    WarningFailure to accurately calculate the cost may lead to incorrect predictions.
  2. Calculate the benefit to the recipient
    Determine the benefit to the individual receiving the altruistic act.
    Pro tipConsider the potential benefits to the recipient, including increased survival and reproduction.
    WarningFailure to accurately calculate the benefit may lead to incorrect predictions.
  3. Calculate the probability of genetic relatedness
    Determine the probability that the recipient carries a copy of the gene for altruism.
    Pro tipConsider the degree of genetic relatedness between the actor and recipient.
    WarningFailure to accurately calculate the probability may lead to incorrect predictions.
  4. Apply Hamilton's rule
    Use the calculated values to determine whether altruism will evolve.
    Pro tipIf the cost to the actor is less than the benefit to the recipient, multiplied by the probability of genetic relatedness, then altruism will evolve.
    WarningFailure to apply the rule correctly may lead to incorrect predictions.

Checklist

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Examples

2 cases
Ground squirrel alarm calls

Ground squirrels will give alarm calls to warn other squirrels of predators, even if it puts them at risk. This behavior can be explained by Hamilton's rule, as the benefit to the recipient (increased survival) is greater than the cost to the actor (increased risk of predation).

OutcomeThe evolution of alarm calls in ground squirrels.
Human altruism

Humans will often engage in altruistic behaviors, such as donating to charity or helping a stranger in need. This behavior can be explained by Hamilton's rule, as the benefit to the recipient (increased well-being) is greater than the cost to the actor (time, money, or effort).

OutcomeThe evolution of altruism in humans.

Common mistakes

3 traps
Incorrect calculation of cost or benefit
Failure to accurately calculate the cost or benefit may lead to incorrect predictions about the evolution of altruism.
Failure to consider genetic relatedness
Ignoring the degree of genetic relatedness between individuals may lead to incorrect predictions about the evolution of altruism.
Misapplication of Hamilton's rule
Failure to apply Hamilton's rule correctly may lead to incorrect predictions about the evolution of altruism.

Origin story

How this framework came to be

Hamilton's rule was first proposed by W.D. Hamilton in 1964 as a way to explain the evolution of altruism in insects. It has since been applied to a wide range of species, including humans, and has become a fundamental concept in evolutionary psychology.

Source

Traced to primary
Source · BOOK
Evolutionary Psychology The New Science of the Mind
David M Buss · 2020
Open source →

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